Snakelocks Anemone

(Anemonia viridis)

Facts

IUCN NOT EVALUATED (NE)

Facts about this animal

Sometimes also referred to as Actinia sulcata, the Snakelocks Anemone has a stout column which widens towards the oral disc and carries 70-384 long, tapering and flexuous tentacles. The base of the column is up to 7 cm wide and the tentacles span 20 cm, specimens living deep are larger. It reaches a height of 8 cm. The tentacles are grey-brown or bright green, whereas the green variety has purple tips. The tentacles bear venomous nettle cells, called cnidocysts, and rarely withdraw into the column, which is reddish or greyish brown. The disk is brown or greyish with white radial lines.

In shallow waters the Snakelocks Anemone may live in great densities, especially where the water is calm, but below it is single. It fights off other species of anemones by striking with its long tentacles. The green colour of the tentacles is due to symbiotic algae, called zooxanthellae. Since the Snakelocks Anemone profits best if these have much light it preferably settles near the surface and is active by day. Specimens that live in depths of 25 m yet fade to grey because the algae do not get enough light to live. It feeds on small fish, crustaceans and mollusks. A number of animals like the Bucchich‘s Goby (Gobius bucchichii), the Leach’s Spider Crab (Inachus phalangium) and the Mysid Shrim (Leptomysis mediterranea) are commensals of the Snakelocks Anemone and are immune against the anemone’s venom. Known predators are octopi, oxystomatid crabs, and fish that find the anemones after high tide when these are left exposed. Snakelocks Anemones preferably consume snails and slugs which other anemones do not like. They also feed on small fish and prawns. The prey is captured and paralyzed by means of the nettling tentacles and transported to the mouth with cilia. Undigested waste is regurgitated back out through the mouth. They may also reabsorb decomposing products of bacteria living in its digestive cavity.

Off the British Isles, the Snakelocks Anemone breeds from June to August. The sexes are separate. Sperms and eggs are released into the water where fertilization takes place. Eggs are provided with zooxanthellae. More often asexual reproduction by longitudinal fission (also budding) is performed. The two new specimens are asymmetric for some time concerning their mouths and rings of tentacles. The whole process of fission just takes 5 minutes to 2 hours.

Did you know?
that the Snakelocks Anemone is used by humans in salad, omelette or fritter after neutralizing the nettle cells with vinegar?

In the Zoo

Why do zoos keep this animal

The Snakelocks Anemone is very impressive considering its two-coloured tentacles and the length of the tentacles. This species is common on rocky seashores, especially in rock pools, and thus may be familiar to some visitors.